Often, today's travel is multi-purpose. The travel intent of most travelers is varied and, often, unanticipated. For example, a traveler, once travel has started, might need additional packing space for gifts or purchases. In this predicament, the traveler often is forced to buy additional luggage, which often is awkward and cumbersome to carry. In a different situation, a traveler might need a smaller luggage case for a short trip, such as a weekend trip. This requires the traveler to have multiple articles of luggage, of varying sizes, to avoid using a cumbersome oversized case for a small side trip. It is for these reasons that expandable and contractible luggage, better to fulfill the needs of the traveler, have been developed.
Conventional, one piece baggage or luggage, like a suitcase, is typically grouped into two material-types: hardside and softside luggage. Expandable luggage is grouped, based on the mechanism of the expandable function, into three sets: telescoping articles, modular or sectioned articles, and accordion type articles. In addition to material and expandable categories, the prior art includes different combinations thereof.
In attempting to overcome the shortcomings of single piece luggage, proposals in the past for expandable luggage have limitations. Modular expanding cases have been developed to overcome restraints of previous telescoping and accordion type cases. Such limitations are exemplified in the telescoping bags, such as described in U.S. Pat. No. 598,095 (1898) requiring one or more overlapping sections, including a lid and additional mid-section over-lapping a bottom piece. Such sections are made of stiff material and must all be carried, with the telescoping bag, whether it is expanded or not. This adds to the weight and bulkiness of the bag. Accordion type cases work on the principle of expanding and contracting overlapping folds of material or pleats similar to those in an accordion. This, again, has the limitation of the additional weight and bulkiness the pleats create, especially when the pleats are in the unused, collapsed position. Also, the accordion construction requires that straps, or other restraints, must be used to hold the pleats closed and is exemplified in the hand baggage of U.S. Pat. No. 1,806,246 (1931) .
Modular cases, in the prior art, all have limitations. Most modular cases are fabricated of components that are made entirely of either flexible or stiff material. U.S. Pat. No. 4,503,955 (1985) describes a modular carrying case of all metal construction with a top and bottom section and one or more interlocking center sections for additional capacity. A user is disadvantaged by the weight of the modular carrying case and its awkward center sections. In U.S. Pat. No. 1,950,118 (1934) the sides of the stiff interlocking mid-sections are collapsible. These collapsible mid-sections are for the purpose of storage and shipping and not necessarily designed such that the mid-sections may be carried inside the luggage and used later, if necessary. Because the sections of the valise are made of leather with a hardened background of cardboard, the case is subject to the limitations of conventional hardside luggage. In U.S. Pat. No. 3,443,671 (1969) a modular case is composed mainly of flexible fabric. Instead of interlocking parts, the expandable carrying case uses slide fasteners, namely zippers, to connect the pieces. This provides for the expandable sections to remain attached to the main body of the case and the sections are expanded by a unique slide fastener arrangement. However, the carrying case is mainly made of fabric and, thus, subject to the limitations of conventional softside cases.
The following two articles of travel luggage are designed as a combination of hardside and softside materials but both are subject to their own design restraints. In U.S. Pat. No. 4,813,520 (1989) a collapsible piece of baggage, comprises externally of a flexible or pliable material and externally of a detachable frame outlining the bag's shape. Such bag is designed to be reduced in size only for storage purposes. The frame is made inefficient by the many small pieces and screws necessary for assembly. The "Simulated Hard Frame Luggage" in U.S. Pat. No. 4,781,278 (1988) is structurally weakened by its only partial hard frame sections in the corners of the luggage, and thus, does not pose the strength attributed to a solid hardside luggage case.